Soil improvement method

Abstract

The invention discloses a soil improvement method, and relates to the technical field of soil improvement. Comprising the following steps: spraying a soil water-retaining agent on the surface of to-be-improved soil, performing powder ridge cultivation, and performing mixed ridging; biogas liquid is introduced into the ridged soil for irrigation, and after standing, irrigated soil is obtained; digging a plurality of pre-buried pits in the irrigation soil, and burying breathable net pipes in the plurality of pre-buried pits; moss mixtures are injected into the breathable net pipes, then soil backfilling is conducted on the multiple pre-buried pits, and loose soil is obtained; after the loose soil is subjected to watering maintenance, the breathable net pipes are taken out, and maintained soil is obtained; and applying a modified charcoal fertilizer to the surface of the maintained soil, ploughing and uniformly mixing, planting leguminous crops, carrying out rotary tillage into the soil after cutting and harvesting, and planting in a manner of crop rotation of different crops, thereby completing the improvement of the soil. According to the improvement method, the porosity and permeability of the hardened soil can be effectively improved, and the water and fertilizer retention capacity of the soil is improved, so that soil hardening is effectively relieved, and the soil fertility is recovered.

Description

Technical Field

[0001] The present application relates to the technical field of soil improvement, and in particular to a soil improvement method. Background Art

[0002] Soil compaction is one of the important manifestations of soil degradation. Soil compaction is a phenomenon in which the soil surface is hardened by the cohesive force after drying due to the lack of organic matter, poor structure, or structural destruction and dispersion of soil materials caused by external factors such as irrigation and rainfall. This phenomenon will reduce the soil's water and fertilizer retention capacity and permeability, thereby affecting the normal growth and development of crops, resulting in a decrease in yield and economic benefits. Soil compaction is the result of the combined action of many factors, and a large part of the compaction of cultivated land soil is caused by humans. Due to the long-term application of nitrogen, phosphorus and potassium fertilizers and serious lack of organic fertilizers, coupled with excessive investment in plastic products, and unscientific farming methods, rotation systems and fertilization methods, the soil upper structure is destroyed, causing the cultivated land soil to compact, and ultimately causing the soil's cultivability to become worse and worse. At present, irrigation or deep plowing is generally used to treat the compaction of cultivated land soil. However, due to the poor permeability of compacted soil, it is difficult to penetrate the entire soil through irrigation, and the water supply inside the soil is still insufficient. The deep plowing effect is relatively short, and the improvement effect on compacted soil is not significant. Based on this, the present application proposes a soil improvement method. Summary of the invention

[0003] The main purpose of this application is to provide a soil improvement method, aiming to solve the technical problem that the improvement effect of existing methods on compacted soil needs to be improved.

[0004] To achieve the above purpose, the present application proposes a soil improvement method, comprising the following steps:

[0005] Spray soil water retaining agent on the surface of the soil to be improved, and carry out powder ridge cultivation and mixed ridge formation;

[0006] Then, biogas liquid is introduced into the ridged soil for irrigation, and after being left to stand, irrigated soil is obtained;

[0007] Digging a plurality of pre-buried pits on the irrigation soil, and burying air-permeable mesh pipes in the plurality of pre-buried pits;

[0008] Injecting a moss mixture into the air-permeable mesh tube, and then backfilling the plurality of pre-buried pits with soil to obtain loose soil;

[0009] After watering and curing the loose soil, the air-permeable mesh tube is taken out to obtain the curing soil;

[0010] Modified biochar fertilizer is applied on the surface of the curing soil, and after tilling and mixing, leguminous crops are planted, and after mowing and harvesting, the soil is tilled into the soil, and then different crops are rotated for planting, thereby completing the soil improvement.

[0011] Optionally, the ingredients of the soil water retaining agent include, by weight: 30-50 parts of porous chitosan gel, 25-40 parts of graphene oxide, 12-25 parts of polyhydroxy alcohol ester, 25-40 parts of zeolite powder, 10-20 parts of diatomaceous earth, 3-6 parts of Bacillus subtilis and 3-6 parts of Bacillus licheniformis.

[0012] Optionally, the preparation step of the porous chitosan gel comprises:

[0013] The γ-polyglutamic acid solution and Tween-20 are stirred and mixed at room temperature, and a porogen is added to obtain a mixed solution;

[0014] Add acetic acid to the chitosan solution, and then drop it into the mixed solution, centrifuge after the reaction, add hydrochloric acid solution to allow gas to escape, add concentrated ammonia water and adjust the pH to 7, and then wash with deionized water and ethanol in sequence to obtain porous chitosan;

[0015] Acrylamide, 2-acrylamide-2-methylpropanesulfonic acid and vinyl pyrrolidone monomers are dissolved in water, and the pH is adjusted to 7-8, and stirred at a stirring rate of 80r / min-120r / min, and then the porous chitosan is added and mixed, and the temperature is raised to 55°C-65°C, and an inert gas is introduced to an oxygen-free state, and a phenolic crosslinking agent is added and reacted for 2h-3h, and then cooled to room temperature and dried to obtain a porous chitosan gel.

[0016] Optionally, the step of spraying a soil water retaining agent on the surface of the soil to be improved, and performing powder ridge cultivation and mixed ridge forming comprises:

[0017] Mix the soil water retaining agent with water in a mass ratio of 1:(100-115) and spray it on the surface of the soil to be improved. The spraying amount is 0.3-0.5kg / m 2 After standing for 2-5 hours, carry out powder ridge cultivation, mix ridge formation, and control the tillage depth to 20-30cm.

[0018] Optionally, the step of introducing biogas liquid into the ridged soil for irrigation and obtaining irrigated soil after standing still comprises:

[0019] Press 50-60m into the ridged soil 3 / mu of irrigation amount is introduced into biogas liquid for irrigation, and after standing for 4-6 hours, irrigated soil is obtained.

[0020] Optionally, the step of digging a plurality of pre-buried pits on the irrigation soil and burying air-permeable mesh pipes in the plurality of pre-buried pits comprises:

[0021] Press 2-3 / m 3 A plurality of pre-buried pits are dug on the irrigation soil with a density of 35-50 cm, and a plurality of air-permeable mesh tubes are vertically buried in the pit walls of the plurality of pre-buried pits, and one end of the plurality of air-permeable mesh tubes is buried in the pre-buried pits, and the other end is exposed to the ground and in contact with the air.

[0022] Optionally, the step of injecting the moss mixture into the air-permeable mesh tube comprises:

[0023] Inject a moss mixture into the breathable mesh tube until the breathable mesh tube is filled; the moss mixture is a mixture of stone moss, water and humus soil in a mass ratio of 1: (1.5-2): (1.5-2).

[0024] Optionally, after watering the loose soil for curing, the step of taking out the air-permeable mesh tube to obtain the cured soil comprises:

[0025] Spray the loose soil with clean water every 2-3 days, with a spraying volume of 5-8m 3 / mu, and after 28-35 days, take out the breathable mesh tube to obtain the curing soil.

[0026] Optionally, the preparation steps of the modified biochar fertilizer include:

[0027] Adding soybean straw biochar to a citric acid solution, stirring at 20-25°C for 1-3h, heating to 55-65°C and keeping the temperature for 22-24h, heating to 115-125°C and keeping the temperature for 80-100min, cooling to room temperature, washing, and drying at 55-65°C to obtain modified biochar;

[0028] The animal manure and crushed corn cobs are mixed in a mass ratio of 1:(1.5-2) and the water content is controlled to be 50-60% to obtain a compost raw material;

[0029] Adding the modified biochar and calcium-based bentonite to the compost raw material, performing aerobic composting, controlling the temperature at 55-65° C., turning the compost pile every 3-7 days, and obtaining modified biochar fertilizer after 50-60 days;

[0030] Wherein, the added amount of the modified biochar is 5-8% of the mass of the compost raw material, and the added amount of the calcium-based bentonite is 2-5% of the mass of the compost raw material.

[0031] Optionally, in the step of planting leguminous crops and tilling the soil after mowing and harvesting, the leguminous crops include one or more of mung beans, soybeans, alfalfa and acacia, and the tillage depth is 10-20 cm.

[0032] This application includes at least the following beneficial effects:

[0033] The present application first applies a soil water retaining agent on the soil to be improved, and then performs powder ridge cultivation to crush the compacted soil, improve the soil pore structure and permeability, and promote the soil to fully absorb the soil water retaining agent, thereby improving the moisture and oxygen content in the soil and alleviating the compaction of the soil. Then, biogas liquid is introduced for irrigation to increase the soil organic matter content and the content of microbial flora in the soil, thereby improving soil fertility. Then, a breathable mesh pipe is buried in the pre-buried pit to create a breathable space in the soil, which is conducive to the entry of moisture and air and promotes soil water storage and moisture retention. At the same time, a moss mixture is injected into the soil to improve the compaction problem of the deep soil. After the moss is decomposed by soil microorganisms, it can effectively improve soil fertility and provide for the growth of plant roots. Nutrients, then watering and curing, so that the soil maintains a certain water content, and promotes the growth of mosses, to achieve the restoration of soil fertility, and then apply modified biochar fertilizer, so that the organic matter colloid therein can form organic-inorganic composite colloids and various microbial aggregates with soil mineral colloids, thereby improving the physical and chemical properties of soil water, fertilizer, gas, heat, etc., to achieve the effect of fertilizing the soil, and then plant leguminous crops, and rotary tillage into the soil after mowing and harvesting, to further achieve the effect of nitrogen fixation and soil fertilization, and then use different crop rotation methods for planting. Since there are many types of fertilizers added in crop rotation, the damage of a single fertilizer to the soil can be reduced, and different crops can effectively absorb the excess nutrients remaining in the soil, further alleviating the speed of soil compaction. After the improved method of this application, the porosity and permeability of compacted soil can be effectively improved, the water and fertilizer retention capacity of the soil can be improved, and it is beneficial for water and fertilizer to penetrate the entire soil, thereby effectively alleviating soil compaction, restoring soil fertility, and facilitating the growth of crops. BRIEF DESCRIPTION OF THE DRAWINGS

[0034] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. It is obvious that the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on the structures shown in these drawings without paying any creative work.

[0035] Figure 1 Schematic diagram of the process of the soil improvement method described in the embodiment of the present application.

[0036] The realization of the purpose, functional features and advantages of this application will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present application to clearly and completely describe the technical solutions in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, not all of the embodiments. Based on the embodiments in the present application, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of this application.

[0038] In view of the technical problems existing in the prior art, the embodiments of the present application provide a soil improvement method, such as Figure 1 As shown, the following steps are included:

[0039] Spray soil water retaining agent on the surface of the soil to be improved, and carry out powder ridge cultivation and mixed ridge formation;

[0040] Then, biogas liquid is introduced into the ridged soil for irrigation, and after being left to stand, irrigated soil is obtained;

[0041] Digging a plurality of pre-buried pits on the irrigation soil, and burying air-permeable mesh pipes in the plurality of pre-buried pits;

[0042] Injecting a moss mixture into the air-permeable mesh tube, and then backfilling the plurality of pre-buried pits with soil to obtain loose soil;

[0043] After watering and curing the loose soil, the air-permeable mesh tube is taken out to obtain the curing soil;

[0044] Modified biochar fertilizer is applied on the surface of the curing soil, and after tilling and mixing, leguminous crops are planted, and after mowing and harvesting, the soil is tilled into the soil, and then different crops are rotated for planting, thereby completing the soil improvement.

[0045] The present application first applies a soil water retaining agent on the soil to be improved, and then performs powder ridge cultivation to crush the compacted soil, improve the soil pore structure and permeability, and promote the soil to fully absorb the soil water retaining agent, thereby improving the moisture and oxygen content in the soil and alleviating the compaction of the soil. Then, biogas liquid is introduced for irrigation to increase the soil organic matter content and the content of microbial flora in the soil, thereby improving soil fertility. Then, a breathable mesh pipe is buried in the pre-buried pit to create a breathable space in the soil, which is conducive to the entry of moisture and air and promotes soil water storage and moisture retention. At the same time, a moss mixture is injected into the soil to improve the compaction problem of the deep soil. After the moss is decomposed by soil microorganisms, it can effectively improve soil fertility and provide for the growth of plant roots. Nutrients, then watering and curing, so that the soil maintains a certain water content, and promotes the growth of mosses, to achieve the restoration of soil fertility, and then apply modified biochar fertilizer, so that the organic matter colloid therein can form organic-inorganic composite colloids and various microbial aggregates with soil mineral colloids, thereby improving the physical and chemical properties of soil water, fertilizer, gas, heat, etc., to achieve the effect of fertilizing the soil, and then plant leguminous crops, and rotary tillage into the soil after mowing and harvesting, to further achieve the effect of nitrogen fixation and soil fertilization, and then use different crop rotation methods for planting. Since there are many types of fertilizers added in crop rotation, the damage of a single fertilizer to the soil can be reduced, and different crops can effectively absorb the excess nutrients remaining in the soil, further alleviating the speed of soil compaction. After the improved method of this application, the porosity and permeability of compacted soil can be effectively improved, the water and fertilizer retention capacity of the soil can be improved, and it is beneficial for water and fertilizer to penetrate the entire soil, thereby effectively alleviating soil compaction, restoring soil fertility, and facilitating the growth of crops.

[0046] As an implementation method of the present application, the ingredients of the soil water-retaining agent include, by weight: 30-50 parts of porous chitosan gel, 25-40 parts of graphene oxide, 12-25 parts of polyhydroxy alcohol ester, 25-40 parts of zeolite powder, 10-20 parts of diatomaceous earth, 3-6 parts of Bacillus subtilis and 3-6 parts of Bacillus licheniformis.

[0047] In the specific implementation process, graphene oxide is obtained by oxidizing original graphene according to the Hummers method, and the specific operation steps are as follows:

[0048] After stirring and mixing graphene, concentrated sulfuric acid, potassium persulfate and phosphorus pentoxide, heat to 80°C in an oil bath and keep warm for 5.0 hours, cool to room temperature, filter and wash to pH 7.0, dry at room temperature for 48 hours, add the product to concentrated sulfuric acid, add potassium permanganate, stir in an ice bath for 1.0 hour, react at 50°C for 40-60 hours, place in ice water, add hydrogen peroxide and continue stirring, stand for 48 hours when bright yellow appears, discard the supernatant to obtain the lower precipitate, wash the lower precipitate to pH 7.0, dry at room temperature for 48 hours, and obtain graphene oxide.

[0049] The polyhydroxy alcohol ester is an esterification product obtained by esterification reaction of a polyol and a long-chain fatty acid, wherein the polyol is one of trimethylolpropane, pentaerythritol, 1,2,5-pentanetriol, and trimethylolpentane, and the long-chain fatty acid is one of n-hexadecanoic acid and n-octadecanoic acid.

[0050] The soil water-retaining agent of the present application is prepared by mixing porous chitosan gel, graphene oxide, polyhydroxy alcohol ester, zeolite powder, diatomaceous earth, Bacillus subtilis and Bacillus licheniformis. The porous chitosan gel has super strong water storage performance and swelling performance, which can improve the water retention capacity of the soil; the hydroxyl, carboxyl and other functional groups on the surface of graphene oxide will adsorb cations in the soil and release hydrogen ions at the same time to improve the acidity and alkalinity of the soil, so that the humus decomposition products are better released, thereby increasing soil fertility, and dozens of layers of oxides on the surface of graphene oxide can form a layer of area with a thickness of about 1nm, which increases its specific surface area, is more conducive to the adsorption of the surface of soil particles, and plays a role in retaining moisture; the polyhydroxy alcohol ester contains polyhydroxy polar ends, which are the same When it contains a non-polar saturated hydrocarbon chain of 16 or 18 carbon lengths, after the polyhydroxy alcohol ester is mixed with the soil, it can form hydrogen bonds with inorganic minerals in the soil to adhere to soil particles, further form larger aggregates, and make the aggregates have larger pores, so that the soil has a higher porosity, the oxygen content of the soil is increased, and the permeability and air permeability of the soil are improved; and the zeolite powder has a rich pore structure inside, which can adsorb a large amount of water molecules, and diatomaceous earth has certain dispersibility and adhesion, which can increase the number of aggregates in the soil, thereby increasing the porosity of the soil, and Bacillus subtilis and Bacillus licheniformis can improve soil fertility, improve soil biological activity, and then improve soil permeability and promote the growth of crop roots. By applying the soil water-retaining agent of the present application, the loss of soil moisture can be effectively reduced, the water and fertilizer retention capacity of the soil can be significantly improved, and the porosity and permeability of the compacted soil can be improved, and the soil oxygen content can be increased, thereby effectively alleviating soil compaction.

[0051] As an implementation method of the present application, the preparation steps of the porous chitosan gel include:

[0052] γ-polyglutamic acid and Tween-20 were stirred and mixed at room temperature in a ratio of 1 g:10 mL, and a porogen was added, wherein K2CO3 was used as the porogen, to obtain a mixed solution, wherein the mass fraction of K2CO3 in the mixed solution was 6%;

[0053] Add acetic acid to the chitosan solution, and then drop it into the mixed solution, centrifuge after the reaction, add hydrochloric acid solution to allow gas to escape, add concentrated ammonia water and adjust the pH to 7, and then wash with deionized water and ethanol in sequence to obtain porous chitosan;

[0054] Acrylamide, 2-acrylamide-2-methylpropanesulfonic acid and vinyl pyrrolidone monomers are dissolved in water, and the pH is adjusted to 7-8, and stirred at a stirring rate of 80r / min-120r / min, and then the porous chitosan is added and mixed, and the temperature is raised to 55°C-65°C, and an inert gas is introduced to an oxygen-free state, and a phenolic crosslinking agent is added and reacted for 2h-3h, and then cooled to room temperature and dried to obtain a porous chitosan gel.

[0055] The present application adopts a gas porogen method, in which a porogen capable of generating gas is added to the reaction system, which generates CO2 gas after encountering acid in the reaction system, thereby causing a porous channel structure to be formed on the surface of the chitosan, so that the specific surface area and porosity of the porous chitosan are significantly improved, and then reacted with acrylamide, 2-acrylamide-2-methylpropane sulfonic acid and vinyl pyrrolidone to prepare a porous chitosan gel with a porous surface, so that it has super strong water absorption capacity, further improving the water storage performance and swelling performance of the porous chitosan gel, and being able to fully absorb water after encountering irrigation water, so that the soil can remain moist for a long time without being easily hardened.

[0056] Specifically, the phenolic crosslinking agent is at least one of catechol, hydroquinone, p-phenylenediamine and o-phenylenediamine.

[0057] As an implementable method of the present application, the steps of spraying a soil water retaining agent on the surface of the soil to be improved, and performing powder ridge cultivation and mixed ridge formation include:

[0058] Mix the soil water retaining agent with water in a mass ratio of 1:(100-115) and spray it on the surface of the soil to be improved. The spraying amount is 0.3-0.5kg / m 2 After standing for 2-5 hours, carry out powder ridge cultivation, mix ridge formation, and control the tillage depth to 20-30cm.

[0059] Specifically, after applying soil water retaining agent on the soil, powder ridge tillage is carried out to crush the compacted soil, improve the soil pore structure, promote the soil to fully absorb the soil water retaining agent, further effectively improve the moisture and oxygen content in the soil, promote the activity of soil microorganisms, and help improve soil fertility.

[0060] As an implementation method of the present application, the step of introducing biogas liquid into the ridged soil for irrigation and obtaining irrigated soil after standing comprises:

[0061] Press 50-60m into the ridged soil 3 / mu of irrigation amount is introduced into biogas liquid for irrigation, and after standing for 4-6 hours, irrigated soil is obtained.

[0062] Specifically, biogas liquid is rich in nutrients such as nitrogen, phosphorus, potassium, etc., which have a significant promoting effect on crop growth. As a liquid organic fertilizer, biogas liquid can be used to irrigate compacted soil, which can effectively increase the content of soil organic matter and the content of microbial flora in the soil, and improve soil fertility.

[0063] As an implementable method of the present application, the step of digging a plurality of pre-buried pits on the irrigation soil and burying air permeable mesh pipes in the plurality of pre-buried pits includes:

[0064] Press 2-3 / m 3 A plurality of pre-buried pits are dug on the irrigation soil with a density of 35-50 cm, and a plurality of air-permeable mesh tubes are vertically buried in the pit walls of the plurality of pre-buried pits, and one end of the plurality of air-permeable mesh tubes is buried in the pre-buried pits, and the other end is exposed to the ground and in contact with the air.

[0065] Specifically, the air-permeable mesh tube is made of a bamboo tube whose wall is covered with irregular small holes.

[0066] The present application increases the air permeability space in the soil by burying a breathable mesh tube in a pre-buried pit, which is beneficial to the entry of water and air, and promotes the entry of a moss mixture into the soil through the breathable mesh tube, thereby effectively improving the compaction problem of deep soil. After the moss is decomposed by soil microorganisms, it can effectively improve soil fertility and provide nutrients for the growth of plant roots.

[0067] As an implementable embodiment of the present application, the step of injecting the moss mixture into the breathable mesh tube includes:

[0068] Inject a moss mixture into the breathable mesh tube until the breathable mesh tube is filled; the moss mixture is a mixture of stone moss, water and humus soil in a mass ratio of 1: (1.5-2): (1.5-2).

[0069] Since humus soil has a loose and porous structure, after it is fully in contact with water, only a small amount of organic matter and solid substances are dissolved, and it has the characteristics of water conservation, moisture retention and fertilizer preservation. The moss mixture of the present application is made of a mixture of stone moss, water and humus soil. When injected into the soil, it can effectively improve the soil pore structure and improve soil fertility.

[0070] As an implementable method of the present application, after watering the loose soil, the step of removing the air permeable mesh tube to obtain the cured soil includes:

[0071] Spray the loose soil with clean water every 2-3 days, with a spraying volume of 5-8m 3 / mu, and after 28-35 days, take out the breathable mesh tube to obtain the curing soil.

[0072] Specifically, spraying clean water during soil maintenance can keep the soil at a certain moisture content, promote the growth of moss, and restore soil fertility.

[0073] As an implementable method of the present application, the preparation steps of the modified biochar fertilizer include:

[0074] Adding soybean straw biochar to a citric acid solution, stirring at 20-25°C for 1-3h, heating to 55-65°C and keeping the temperature for 22-24h, heating to 115-125°C and keeping the temperature for 80-100min, cooling to room temperature, washing, and drying at 55-65°C to obtain modified biochar;

[0075] The animal manure and crushed corn cobs are mixed in a mass ratio of 1:(1.5-2) and the water content is controlled to be 50-60% to obtain a compost raw material;

[0076] Adding the modified biochar and calcium-based bentonite to the compost raw material, performing aerobic composting, controlling the temperature at 55-65° C., turning the compost pile every 3-7 days, and obtaining modified biochar fertilizer after 50-60 days;

[0077] Wherein, the added amount of the modified biochar is 5-8% of the mass of the compost raw material, and the added amount of the calcium-based bentonite is 2-5% of the mass of the compost raw material.

[0078] The present application applies modified biochar fertilizer to the soil before planting crops to improve soil fertility. The modified biochar fertilizer uses acid-treated soybean straw biochar to aerobically compost animal manure and crushed corn cobs, and calcium-based bentonite is added to promote composting of the pile. The organic matter colloids formed after the decomposition of animal manure and crushed corn cobs can form organic-inorganic composite colloids and various microbial aggregates with soil mineral colloids, so that the obtained modified biochar fertilizer can provide a large amount of organic matter and various microorganisms, thereby improving the physical and chemical properties of the soil such as water, fertilizer, air, and heat, has a good soil fertilization effect, and is beneficial to the growth of crops.

[0079] As an implementable method of the present application, in the step of planting leguminous crops and tilling the soil after mowing and harvesting, the leguminous crops include one or more of mung beans, soybeans, alfalfa and acacia, and the tillage depth is 10-20 cm.

[0080] Since the roots of leguminous crops contain rhizobia, which can fix nitrogen and fertilize the soil, first planting leguminous crops on improved compacted soil and rotary tilling the soil after harvesting can better improve the soil's water and fertilizer retention and fertilizer supply capabilities. Mung beans, soybeans, alfalfa and acacia, as perennial low plants, can also effectively change the soil bulk density and slow down water evaporation, which is beneficial to the subsequent planting of other crops.

[0081] The above technical solution of the present application is described in detail below in conjunction with specific embodiments.

[0082] Example 1

[0083] A soil improvement method comprises the following steps:

[0084] Mix the soil water retaining agent with water in a mass ratio of 1:108 and spray it on the surface of the soil to be improved. The spraying amount is 0.4kg / m 2 After standing for 3 hours, powder ridge cultivation was carried out, mixed ridges were formed, and the tillage depth was controlled to be 25 cm; wherein the ingredients of the soil water retaining agent include: 400 g of porous chitosan gel, 320 g of graphene oxide, 190 g of polyhydroxy alcohol ester, 320 g of zeolite powder, 150 g of diatomaceous earth, 45 g of Bacillus subtilis and 45 g of Bacillus licheniformis;

[0085] Then press 55m into the ridged soil 3 / mu of irrigation volume, introduce biogas liquid for irrigation, and after standing for 5 hours, obtain irrigated soil;

[0086] Press 2 / m 3 A plurality of pre-buried pits are dug on the irrigation soil at a density of 42 cm in depth, and a plurality of air-permeable mesh pipes are vertically buried in the walls of the plurality of pre-buried pits, with one end of the air-permeable mesh pipe exposed to the ground and in contact with the air;

[0087] Injecting a moss mixture into the air permeable mesh tube until the air permeable mesh tube is filled, wherein the moss mixture is a mixture of stone moss, water and humus in a mass ratio of 1:1.75:1.75, and then backfilling the multiple pre-buried pits with soil to obtain loose soil;

[0088] Every 2 days, the loose soil is sprayed with clean water for maintenance, with a spraying volume of 6.5m 3 / mu, after 31 days, the air permeable mesh tube is removed to obtain the curing soil;

[0089] The soybean straw biochar was added to the citric acid solution, stirred at 22°C for 2h, then heated to 60°C and kept warm for 23h, then heated to 120°C and kept warm for 90min, cooled to room temperature, washed, and dried at 60°C to obtain modified biochar;

[0090] The animal manure and the crushed corn cobs are mixed in a mass ratio of 1:1.75 and the water content is controlled to be 55% to obtain a compost raw material;

[0091] Adding the modified biochar and calcium-based bentonite to the compost raw material, performing aerobic composting, controlling the temperature at 60° C., turning the compost pile every 5 days, and obtaining modified biochar fertilizer after 55 days;

[0092] Wherein, the addition amount of the modified biochar is 6.5% of the mass of the compost raw material, and the addition amount of the calcium-based bentonite is 3% of the mass of the compost raw material;

[0093] Modified biochar fertilizer is applied on the surface of the curing soil, and after tilling and mixing, mung bean, soybean, alfalfa and acacia are planted, and after mowing and harvesting, the soil is rotary tilled to a depth of 15 cm, and then different crops are rotated for planting to complete the soil improvement.

[0094] Example 2

[0095] A soil improvement method comprises the following steps:

[0096] Mix the soil water retaining agent with water in a mass ratio of 1:100 and spray it on the surface of the soil to be improved. The spraying amount is 0.3kg / m 2 After standing for 2 hours, powder ridge cultivation was carried out, mixed ridges were formed, and the tillage depth was controlled to be 20 cm; wherein the ingredients of the soil water retaining agent include: 300 g of porous chitosan gel, 250 g of graphene oxide, 120 g of polyhydroxy alcohol ester, 250 g of zeolite powder, 100 g of diatomaceous earth, 30 g of Bacillus subtilis and 30 g of Bacillus licheniformis;

[0097] Then press 50m into the ridged soil. 3 / mu of irrigation volume, biogas liquid was introduced for irrigation, and after standing for 4 hours, irrigated soil was obtained;

[0098] Press 2 / m 3 A plurality of pre-buried pits are dug on the irrigation soil at a density of 35 cm, and a plurality of air-permeable mesh pipes are vertically buried in the walls of the plurality of pre-buried pits, with one end of the air-permeable mesh pipe exposed to the ground and in contact with the air;

[0099] Injecting a moss mixture into the air permeable mesh tube until the air permeable mesh tube is filled, wherein the moss mixture is a mixture of stone moss, water and humus in a mass ratio of 1:1.5:1.5, and then backfilling the multiple pre-buried pits with soil to obtain loose soil;

[0100] Every 2 days, the loose soil is sprayed with clean water for maintenance, with a spraying volume of 5m 3 / mu, after 28 days, the air permeable mesh tube is removed to obtain the curing soil;

[0101] The soybean straw biochar was added to the citric acid solution, stirred at 20°C for 1 hour, then heated to 55°C and kept warm for 24 hours, then heated to 115°C and kept warm for 100 minutes, cooled to room temperature, washed, and dried at 55°C to obtain modified biochar;

[0102] The animal manure and the crushed corn cobs are mixed in a mass ratio of 1:1.5 and the water content is controlled to be 50% to obtain a compost raw material;

[0103] Adding the modified biochar and calcium-based bentonite to the compost raw material, performing aerobic composting, controlling the temperature at 55° C., turning the compost pile every 3 days, and obtaining modified biochar fertilizer after 50 days;

[0104] Wherein, the addition amount of the modified biochar is 5% of the mass of the compost raw material, and the addition amount of the calcium-based bentonite is 2% of the mass of the compost raw material;

[0105] Modified biochar fertilizer is applied on the surface of the curing soil, and after tilling and mixing, mung bean, soybean, alfalfa and acacia are planted, and after mowing and harvesting, the soil is rotary tilled to a depth of 10 cm, and then different crops are rotated for planting to complete the soil improvement.

[0106] Example 3

[0107] A soil improvement method comprises the following steps:

[0108] Mix the soil water retaining agent with water in a mass ratio of 1:115 and spray it on the surface of the soil to be improved. The spraying amount is 0.5kg / m 2 After standing for 5 hours, powder ridge cultivation was carried out, mixed ridges were formed, and the tillage depth was controlled to be 30 cm; wherein the ingredients of the soil water retaining agent include: 500 g of porous chitosan gel, 400 g of graphene oxide, 250 g of polyhydroxy alcohol ester, 400 g of zeolite powder, 200 g of diatomaceous earth, 60 g of Bacillus subtilis and 60 g of Bacillus licheniformis;

[0109] Then press 60m into the ridged soil. 3 / mu of irrigation volume, biogas liquid was introduced for irrigation, and after standing for 6 hours, irrigated soil was obtained;

[0110] Press 3 / m 3 A plurality of pre-buried pits are dug on the irrigation soil at a density of 50 cm, and a plurality of air-permeable mesh pipes are vertically buried in the walls of the plurality of pre-buried pits, with one end of the air-permeable mesh pipe exposed to the ground and in contact with the air;

[0111] Injecting a moss mixture into the air permeable mesh tube until the air permeable mesh tube is filled, wherein the moss mixture is a mixture of stone moss, water and humus in a mass ratio of 1:2:2, and then backfilling the multiple pre-buried pits with soil to obtain loose soil;

[0112] Every 3 days, the loose soil is sprayed with clean water for maintenance, with a spraying volume of 8m 3 / mu, after 35 days, the air permeable mesh tube is removed to obtain the curing soil;

[0113] The soybean straw biochar was added to the citric acid solution, stirred at 25°C for 1 hour, then heated to 65°C and kept warm for 22 hours, then heated to 125°C and kept warm for 80 minutes, cooled to room temperature, washed, and dried at 65°C to obtain modified biochar;

[0114] The animal manure and the crushed corn cobs are mixed in a mass ratio of 1:2 and the water content is controlled to be 60% to obtain a compost raw material;

[0115] Adding the modified biochar and calcium-based bentonite to the compost raw material, performing aerobic composting, controlling the temperature at 65° C., turning the compost pile every 7 days, and obtaining modified biochar fertilizer after 60 days;

[0116] Wherein, the addition amount of the modified biochar is 8% of the mass of the compost raw material, and the addition amount of the calcium-based bentonite is 5% of the mass of the compost raw material;

[0117] Modified biochar fertilizer is applied on the surface of the curing soil, and after tilling and mixing, mung bean, soybean, alfalfa and acacia are planted, and after mowing and harvesting, the soil is rotary tilled to a depth of 20 cm, and then different crops are rotated for planting to complete the soil improvement.

[0118] Comparative Example 1

[0119] Compared with Example 1, the soil water-retaining agent of the present application is replaced with polyacrylamide, and the remaining steps are the same.

[0120] Comparative Example 2

[0121] Compared with Example 2, the moss mixture is not injected into the air-permeable mesh tube, and the remaining steps are the same.

[0122] Comparative Example 3

[0123] Compared with Example 3, when preparing the modified biochar fertilizer, the modified biochar is replaced with soybean straw biochar, and the remaining steps are the same.

[0124] Test example

[0125] The compacted soil was selected for the test and a small plot comparison test was conducted with a plot area of ​​24m 2 (6m×4m), randomized block arrangement, 6 treatments were designed in the experiment, and the experimental soil was improved according to the improvement methods of the embodiments and comparative examples in each treatment. After the improvement, the same variety of strawberries were planted in each plot, and three complete harvests were randomly performed in each plot at the early, middle and late stages of strawberry harvest. The three harvests in each plot were taken as the total yield of each plot, and 5 plants were randomly selected each time to measure the single fruit weight of strawberries, and the average single fruit weight of strawberries was calculated. The measurement results are shown in Table 1 below.

[0126] Table 1

[0127]

[0128]

[0129] As shown in Table 1, after the compacted soil was improved by the improvement method of the present application, the total yield of strawberries could reach 3890.67 kg·hm -2 , the average single fruit weight reaches more than 27g, while in comparative example 1, the soil water retaining agent is replaced with conventional polyacrylamide, which has a certain effect on the yield and fruit weight of strawberries, indicating that the soil water retaining agent of the present application is more conducive to improving the water and fertilizer retention capacity of the soil than conventional polyacrylamide, and thus is beneficial to the growth of crops; in comparative example 2, no moss mixture is injected into the soil, and moss can effectively alleviate soil compaction and provide fertility for the soil, so comparative example 2 has a certain effect on the growth of strawberries; in comparative example 3, the soybean straw biochar is not modified, and the present application performs acid treatment on the soybean straw biochar, which can increase the proportion of water-soluble organic matter in the soybean straw biochar, promote the supply of nutrients in the composting process, and enable the modified biochar fertilizer to provide a large amount of organic matter and various microorganisms to achieve the effect of fertilizing the soil, so the yield and fruit weight of strawberries in comparative example 3 are reduced.

[0130] The above description is only an optional embodiment of the present application, and does not limit the patent scope of the present application. All equivalent structural transformations made by using the contents of the present application specification and drawings under the inventive concept of the present application, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present application.

Claims

1. A soil improvement method, characterized in that: The following steps are involved: Spray soil water retaining agent on the surface of the soil to be improved, and carry out powder ridge cultivation and mixed ridge formation; Then, biogas liquid is introduced into the ridged soil for irrigation, and after being left to stand, irrigated soil is obtained; Digging a plurality of pre-buried pits on the irrigation soil, and burying air-permeable mesh pipes in the plurality of pre-buried pits; Injecting a moss mixture into the air-permeable mesh tube, and then backfilling the plurality of pre-buried pits with soil to obtain loose soil; After watering and curing the loose soil, the air-permeable mesh tube is taken out to obtain the curing soil; Modified biochar fertilizer is applied on the surface of the curing soil, and after tilling and mixing, leguminous crops are planted, and after mowing and harvesting, the soil is tilled into the soil, and then different crops are rotated for planting, thereby completing the soil improvement.

2. The soil improvement method according to claim 1, characterized in that: The soil water retaining agent comprises, by weight, 30-50 parts of porous chitosan gel, 25-40 parts of graphene oxide, 12-25 parts of polyhydroxy alcohol ester, 25-40 parts of zeolite powder, 10-20 parts of diatomaceous earth, 3-6 parts of Bacillus subtilis and 3-6 parts of Bacillus licheniformis.

3. The soil improvement method according to claim 2, characterized in that: The preparation steps of the porous chitosan gel include: The γ-polyglutamic acid solution and Tween-20 are stirred and mixed at room temperature, and a porogen is added to obtain a mixed solution; Add acetic acid to the chitosan solution, and then drop it into the mixed solution, centrifuge after the reaction, add hydrochloric acid solution to allow gas to escape, add concentrated ammonia water and adjust the pH to 7, and then wash with deionized water and ethanol in sequence to obtain porous chitosan; Acrylamide, 2-acrylamide-2-methylpropanesulfonic acid and vinyl pyrrolidone monomers are dissolved in water, and the pH is adjusted to 7-8, and stirred at a stirring rate of 80r / min-120r / min, and then the porous chitosan is added and mixed, and the temperature is raised to 55°C-65°C, and an inert gas is introduced to an oxygen-free state, and a phenolic crosslinking agent is added and reacted for 2h-3h, and then cooled to room temperature and dried to obtain a porous chitosan gel.

4. The soil improvement method according to claim 3, characterized in that: The steps of spraying a soil water retaining agent on the surface of the soil to be improved, performing powder ridge cultivation, and mixed ridge forming include: Mix the soil water retaining agent with water in a mass ratio of 1:(100-115) and spray it on the surface of the soil to be improved. The spraying amount is 0.3-0.5kg / m 2 After standing for 2-5 hours, carry out powder ridge cultivation, mix ridge formation, and control the tillage depth to 20-30cm.

5. The soil improvement method according to claim 1, characterized in that: The step of introducing biogas liquid into the ridged soil for irrigation and obtaining irrigated soil after standing still comprises: Press 50-60m into the ridged soil 3 / mu of irrigation amount is introduced into biogas liquid for irrigation, and after standing for 4-6 hours, irrigated soil is obtained.

6. The soil improvement method according to claim 1, characterized in that: The step of digging a plurality of pre-buried pits on the irrigation soil and burying air-permeable mesh pipes in the plurality of pre-buried pits comprises: Press 2-3 / m 3 A plurality of pre-buried pits are dug on the irrigation soil with a density of 35-50 cm, and a plurality of air-permeable mesh tubes are vertically buried in the pit walls of the plurality of pre-buried pits, and one end of the plurality of air-permeable mesh tubes is buried in the pre-buried pits, and the other end is exposed to the ground and in contact with the air.

7. The soil improvement method according to claim 1, characterized in that: The step of injecting the moss mixture into the air-permeable mesh tube comprises: Inject a moss mixture into the breathable mesh tube until the breathable mesh tube is filled; the moss mixture is a mixture of stone moss, water and humus soil in a mass ratio of 1: (1.5-2): (1.5-2).

8. The soil improvement method according to claim 1, characterized in that: After the loose soil is watered and cured, the air permeable mesh tube is taken out to obtain the cured soil, comprising: Spray the loose soil with clean water every 2-3 days for maintenance, with a spraying volume of 5-8m 3 / mu, and after 28-35 days, take out the breathable mesh tube to obtain the curing soil.

9. The soil improvement method according to claim 1, characterized in that: The preparation steps of the modified biochar fertilizer include: Adding soybean straw biochar to a citric acid solution, stirring at 20-25°C for 1-3h, heating to 55-65°C and keeping the temperature for 22-24h, heating to 115-125°C and keeping the temperature for 80-100min, cooling to room temperature, washing, and drying at 55-65°C to obtain modified biochar; The animal manure and crushed corn cobs are mixed in a mass ratio of 1:(1.5-2) and the water content is controlled to be 50-60% to obtain a compost raw material; Adding the modified biochar and calcium-based bentonite to the compost raw material, performing aerobic composting, controlling the temperature at 55-65° C., turning the compost pile every 3-7 days, and obtaining modified biochar fertilizer after 50-60 days; Wherein, the added amount of the modified biochar is 5-8% of the mass of the compost raw material, and the added amount of the calcium-based bentonite is 2-5% of the mass of the compost raw material.

10. The soil improvement method according to claim 1, characterized in that: In the step of planting leguminous crops and rotary tilling the soil after mowing and harvesting, the leguminous crops include one or more of mung beans, soybeans, alfalfa and acacia, and the rotary tillage depth is 10-20 cm.

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